1. Field of the Device
The present device relates to a cover structure for an electronic circuit module.
2. Description of the Related Art
For example, in a television tuner, an entire electronic circuit portion that handles high-frequency signals is covered with a metallic cover for electromagnetically shielding the electronic circuit portion from an external environment. A portion of the cover is soldered to a substrate of an electronic circuit. In order to increase soldering performance, various methods are proposed.
As one method, in order to prevent dispersion of solder heat at a soldering portion of the cover, providing a through hole near the soldering portion of the cover is generally known.
FIG. 5 shows a portion of an existing cover structure 901 that is described in Japanese Unexamined Patent Application Publication No. 2001-36278. A through hole 902a is provided near a projecting portion 902b of a shield plate 902, which is part of a cover. The projecting portion 902b and a substrate 903 are joined to each other with solder 904.
However, when, in the existing cover structure 901, an outside force generated by, for example, handling is transmitted to the shield plate 902, the shield plate 902 is deformed. This causes even the projecting portion 902b, which is provided in the same plane as the shield plate 902, to be deformed. Therefore, an outside force resulting from the deformation of the projecting portion 902b is also transmitted to the solder 904 that joins the projecting portion 902b and the substrate 903 to each other. This may cause the solder 904 to crack.